1. Field of the Invention
The present invention relates to a cosmetic pencil structure which is filled with stick shaped cosmetics such as lip color pencil, eye shadow pencil, cheek color pencil and eyebrow pencil, for example in a cylindrical shaft.
2. Description of the Related Art
As a conventional cosmetic pencil, cosmetics with a shaft body (cylindrical shaft) that is cylindrical in shape filled with a cosmetic material or a pigment replacing the lead of a pencil (for example, lip color pencil, eyebrow pencil, eye shadow pencil and the like) are known.
The cosmetic pencil is usually provided with a cylindrical shaft for storing the cosmetic material, a tail cap to be fitted at the rear end side of the cylindrical shaft, and a cap member for covering the tip end side of the cylindrical shaft.
Further, to store the cosmetic material inside the cosmetic pencil, for example, a method of filling the melted cosmetic material from the rear end side of the cylindrical shaft (back filling method), and then cooling and setting it, is used. Then, the cosmetic material set in the cylindrical shaft is fixed only by contact (friction) with the inner surface of the cylindrical shaft.
The cylindrical shaft is required to have a cutting characteristic so that cutting is easily carried out with a sharpener or the like, a molding characteristic for easily shaping a cylindrical shape, and an anti-chemical characteristic so it is not damaged by the cosmetic components that are stored therein. Conventionally, as the material for the cylindrical shaft, wood, synthetic wood, plastic (resin) material such as polyethylene (PE) or the like has been used. In the case wood is used, it is manufactured from a wood panel by shape-out processing. Further, in the case of synthetic wood, resin material such as or polyethylene (PE), and the like, a cylindrical shaft is molded by an extrusion method, and thereafter a pointing processing (beveling the outer surface shape of the tip end), and a hollowing processing for tail cap fitting, and the like are carried out.
Further, the cosmetic pencil is often arranged in a showcase in various colors so that it is easy for consumers to select the favored color. However, in cosmetic pencils formed with the conventional materials including those made of polyethelene (PE) resin, the color of the cosmetic material inside cannot be determined since the cylindrical shaft is not transparent. Therefore, approximately the same color is marked on the peripheral surface or the tail cap of the cylindrical shaft to display the color of the cosmetic material.
However, in the case of marking the same color of the stored cosmetic material to the peripheral surface or the tail cap of the cylindrical shaft, there are the following shortcomings:
(1) since the characteristics of the components of the paint differed to the main components of the cosmetic material, it is difficult to show the color and feel of the actual cosmetic material by paint.
(2) if the cosmetic material differs then the paint differs, so that it is necessary to wash the paint hopper (case) and the like each time, which caused the painting process to be laborious and time-consuming, and therefore is not suitable in the case where various kinds of products are manufactured in small quantities. In this case, by making the cylindrical shaft transparent, the color shade of the cosmetic material inside may be visualized.
However, a conventional transparent resin with polyvinyl chloride (PVC), or the like, as the base material has extremely poor cutting characteristics, so that it is not at all suitable as the material for the cylindrical shaft of the cosmetic pencil.
Further, the conventional cosmetic pencil is fixed only by the contact (friction) of the stored cosmetic material with the inner surface of the cylindrical shaft, but the cosmetic material has a smooth surface characteristic so the cosmetic material may be applied onto the skin smoothly. Also if the inner surface of the material of the cylindrical shaft is flat it becomes slippery. Therefore, there is fear that, when the cosmetic material is pressed during use, or if the cosmetic pencil is given shock such as by being dropped, the cosmetic material would move in the shaft direction or rotate within the cylindrical shaft.
With the conventional cosmetic pencil, a step processing (refer to FIG. 8B) is carried out to the inner wall of the cylindrical shaft obtained by extrusion to prevent movement of the cosmetic material, a partial screw thread cutting processing is conducted (refer to FIG. 8C), or both the step processing and screw thread cutting processing are conducted, so that friction becomes larger.
However, in this case, a processing margin for the step or the convex-concave of the screw thread is necessary, so that the thickness of the cylindrical shaft at the time of extrusion must be made larger (for example, for an outer diameter of 7.65 mm the hole diameter is 4 mm, refer to FIG. 9), and since cutting processing and the like of for the step and screw thread is necessary, in addition to the pointing (beveling of the tip end peripheral surface) processing and the hollowing processing performed after extrusion, there is a problem that labor and time is needed for the cutting processing and disposal of the chips, to increase the cost.
In order to solve the problems of the conventional cosmetic pencil, the present inventors have carried out earnest research of a resin that is easy to shape as well as having a good cutting characteristic, and after formation has a transparency so that the color tone of the cosmetic material inside may be distinguished. As a result, a composite material of an olefin-based polymer with color tone of the cosmetic material inside may be distinguished. As a result, a composite material of an olefin-based polymer with a polypropylene (PP) as a base material, which has been deemed unsuitable conventionally since it is hard and poor in cutting characteristic, mixed with other materials to improve a cutting characteristic, has been found to comprise these conditions.
The present invention has been made in view of the above, and an object of the present invention is therefore to provide a cosmetic pencil made of a material with which the color tone of the cosmetic material may be distinguished from the outside, which is cuttable, and to which processing to prevent the cosmetic material inside the shaft from moving may be easily carried out.
In order to achieve the above objects, the cosmetic pencil of the present invention uses the following measures.
Namely, the cosmetic pencil of the present invention is characterized in that a transparent shaft body having a good cutting property is formed from a composite material of olefin-based polymer having polypropylene as the base material, and a softened cosmetic material is filled and set in a shaft hole of the shaft body, and the tip end side of the shaft body is cut to use the cosmetic material.
Here, the composite material of the olefin-based polymer with the polypropylene as the base material, may be for example, a shaft body includes those in which even if the transparency is low, the color of the cosmetic material filled inside may be determined.
Further, the transparent shaft body may be provided with moving prevention means for the cosmetic material so that the filled cosmetic material does not move inside the shaft hole. The moving prevention means may be formed by injection molding method.
With this structure, by forming the cylindrical shaft from a transparent composite material of olefin-based polymer, the color of the cosmetic material stored can be directly seen from the outside, so that the color tone of the cosmetic material may be distinguished without the conventional marking of the cylindrical shaft or the tail cap with the same color. Further, the olefin-based polymer with the polypropylene as the base material is suitable for injection molding, and by molding the moving prevention means by the injection molding method, secondary processing such as a cutting processing is not required unlike the conventional case, work for the cutting processing and disposal of the chips is not required, thereby realizing reduction in cost.
Further, although the composite material of the olefin-based polymer is not completely transparent after formation, it has enough transparency to distinguish the color tone of the cosmetic material stored in the shaft from the outside.
The shaft body may be formed as a cylindrical shape in cross-section, or may be formed as other shapes (such as a polygon).
Illustration of the moving prevention means in the present invention
The moving prevention means of the present invention may be those in the following cases.
Namely, in the case the moving prevention means is a ring convex portion provided along the circumferential direction of the inner surface of the rear end side of the shaft hole, the filled cosmetic material hardens and sets surrounding the ring convex portion, to stop the cosmetic material in the shaft hole moving in the shaft direction. Further, in the case that the moving prevention means is a tapered surface where the inner diameter of the shaft hole at the tip end side is smaller than that at the rear end side, the tapered surface prevents the cosmetic material in the shaft hole moving to the tip end direction. The rear end of the cylindrical shaft is usually fitted with the tail cap, and by this tail cap moving of the cosmetic material to the rear end direction may be prevented, so that by providing the tapered surface, the moving of the cosmetic material in the shaft direction may be prevented.
In the case that the moving prevention means is provided by forming the inner peripheral surface inside the shaft hole into a polygon in cross-section, or in the case that a knurled vertical rib and/or vertical groove is formed in the inner surface of the shaft hole along the shaft direction, the cosmetic material filled in the corner portion of the polygon or the vertical rib and/or the vertical groove is set hard, it prevents the cosmetic material in the shaft hole from moving in the circumferential direction.
The cosmetic pencil according to the present invention is realized also when the below structure is further added to the above necessary structural elements. The added structural elements mean that the tip end side outer peripheral surface of the cylindrical shaft has a beveled shape. This shape can be obtained at the time of injection molding, in contrast to the conventional case where beveling (pointing) processing is conducted after extrusion. Therefore, the time for cutting processing and disposal of the chips is not required, thereby realizing cost reduction.